Slime control compositions and their use

ABSTRACT

The present invention relates to certain processes and compositions useful for inhibiting the growth of slime in water and, in particular, water used for industrial purposes; for example, in the manufacture of pulp paper, in the manufacture of paper, in cooling water systems and in effluent water treatment. The novel processes and compositions of the present invention are processes or mixtures which show unexpected synergistic activity against microorganisms, including bacteria, fungi and algae, which produce slime in aqueous systems or bodies which are objectionable from either an operational or aesthetic point of view. Specifically, the invention is directed to the use of compositions comprising a combination of a bromonitrostyrene and cetyl trimethyl ammonium bromide.

United States Patent [191 Shema et a1.

[ Aug. 13, 1974 SLIME CONTROL COMPOSITIONS AND THEIR USE [63] Continuation-impart of Ser. No. 271,459, July 13, 1972, which is a continuation-in-part of Ser. No. 000,464, Jan. 2, 1970, abandoned.

[52] US. Cl 424/329, 71/67, 162/161, 424/349 [51] Int. Cl. A0ln 9/02, AOln 9/20 [58] Field of Search 424/329, 349; 71/67; 162/161 [56] References Cited UNITED STATES PATENTS 3,231,509 l/l966 Shema 252/177 3,300,373 l/l967 Wolfson 162/190 3,342,671 9/1967 Sousa et al 424/349 3,519,414 7/1970 Nikawitz et al 71/67 3,565,927 2/1971 Wakeman et a1 71/67 OTHER PUBLICATIONS Chemical Abstracts 70:67163u (1969). Merck Index 8th ed., 1968 pg. 226.

Primary Examiner-Albert T. Meyers Assistant Examiner-Leonard Schenkman Attorney, Agent, or FirmAlexander D. Ricci; Eugene F. Miller 1 5 ABSTRACT The present invention relates to certain processes and compositions useful for inhibiting the growth of slime in water and, in particular, water used for industrial purposes; for example, in the manufacture of pulp paper, in the manufacture of paper, in cooling water systems and in effluent water treatment. The novel processes and compositions of the present invention are processes or mixtures which show unexpected synergistic activity against microorganisms, including bacteria, fungi and algae, which produce slime in aqueous systems or bodies which are objectionable from either an operational or aesthetic point of view. Specifically, the invention is directed to the use of compositions comprising a combination of a bromonitrostyrene and cetyl trimethyl ammonium bromide.

8 Claims, No Drawings promotes corrosion.

I through the cooling system plugs and fouls lines, valves,

SLIME CONTROL COMPOSITIONS AND THEIR USE This Application is a Continuation-in-Part of copending application Ser. No. 271,459 Filed July 13, 1972,

which in turn is a continuation-in-part of application Ser. No. 464, Filed Jan. 2, 1970, now abandoned.

BACKGROUND OF THE INVENTION The formation of slime by microorganisms is a problem which attends many systems. For example, lagoons, lakes, ponds, pools, and such systems as cooling water systems and pulp and paper mill systems all possess conditions which are conducive to the growth and reproduction of slime-forming microorganisms. In both once-through and recirculating cooling systems, for example, which employ large quantities of water as a cooling medium, the formation of slime by microorganisms is an extensive and constant problem.

Airborne organisms are readily entrained in the water from cooling towers and find this warm medium an ideal environment for growth and multiplication. Aerobic and heliotropic organisms flourish on the tower proper while other organisms colonize and grow in such areas as the tower sump and the piping and passages of the cooling system. Such slime serves to deteriorate the tower structure in the case of wooden towers. In addition, the deposition of slime on metal surfaces Furthermore, slime carried strainers, etc. and deposits on heat exchange surfaces. In the latter case, the impedance of heat transfer can greatly reduce the efficiency of the cooling system.

In pulp and paper mill systems, slime formed by microorganisms is also frequently and, in fact, commonly encountered. Fouling or plugging by slime also occurs in the case of pulp and paper mill systems. Of greater significance, the slime becomes entrained in the paper produced to cause breakouts on the paper machines with consequent work stoppages and the loss of production time or unsightly blemishes in the final product which results in rejects and wasted output. The previously discussed problems have resulted in the extensive utilization of biocides in cooling water and pulp and paper mill systems. Materials which have enjoyed widespread use in such applications include chlorine, organo-mercurials, chlorinated phenols, organobromines, and various organo-sulfur compounds. All of these compounds are generally useful for this purpose but each is attended by a variety of impediments. For example, chlorination is limited both by its specific toxicity for slime-forming organisms at economic levels and by the ability of chlorine to react which results in the expenditure of the chlorine before its full biocidal function may be achieved. Other biocides are attended by odor problems and hazards in respect to storage, use or handling which limit their utility. To date, no one compound or type of compound has achieved a clearly established predominance in respect to the applications discussed. Likewise, lagoons, ponds, lakes and even pools, either used for pleasure purposes or used for industrial purposes for the disposal and storage of industrial wastes, become, during the warm weather, besieged by slime due to microorganism growth and reproduction. In the case of the recreational areas, the problem of infection, etc. is obvious. In the case of industrial storage or disposal of industrial materials, the

microorganisms cause additional problems which must be eliminated prior to the materials use or the waste is treated for disposal.

Naturally, economy is a major consideration in respect to all of these biocides. Such economic considerations attach to both the cost of the biocide and the expense of its application. The cost-performance index of any biocide is derived from the basic cost of the material, its effectiveness per unit of weight, the duration of its biocidal or biostatic effect in the system treated, and the ease and frequency of its addition to the system treated. To date, none of the commercially available biocides have exhibited a prolonged biocidal effect. Instead, their effectiveness is rapidly reduced as the result of exposure to physical conditions such as temperature, association with ingredients contained by the system toward which they exhibit an affinity or substantivity, etc., with a resultant restriction or elimination of their biocidal effectiveness.

As a consequence, the use of such biocides involves their continuous or frequent addition to systems to be treated and their addition to a plurality of points or zones in the systems to be treated. Accordingly, the cost of the biocide and the labor cost of such means of applying it are considerable. In other instances, the difficulty of access to the zone in which slime formation is experienced precludes the effective use of a biocide. For example, in a particular system there is no access to an area at which slime formation occurs and it may only be applied at a point which is upstream in the flow system. However, the physical or chemical conditions, e.g. chemical reactivity, thermal degradation, etc. which exist between the point at which the biocide may be added to the system and the point at which its biocidal effect is desired render the effective use of a biocide impossible.

Similarly, in a system experiencing relatively slow flow, such as a paper mill, if a biocide is added at the beginning of the system, its biocidal effect may be completely dissipated before it has reached all of the points at which this effect is desired or required. As a consequence, the biocide must be added at a plurality of points, and even then a graduated biocidal effect will be experienced between one point of addition to the system and the next point downstream at which the biocides may be added. In addition to the increased cost of utilizing and maintaining plural feed points, gross ineconomies in respect to the cost of the biocide are experienced. Specifically, at each point of addition, an excess of the biocide is added to the system in order to compensate for that portion of the biocide which will be expended in reacting with other constituents present in the system or experience physical changes which impair its biocidal activity.

It is an object of the present invention to provide methods and compositions for controlling slimeforrning microorganisms in aqueous systems such as cooling water systems and pulp and paper mill systems, and for controlling slime formation or microorganism populations in aqueous bodies in general. Moreover, another object of the invention is the provision of methods and compositions for controlling slimeforming microorganisms in any aqueous system which is conducive to the growth and reproduction of microorganisms and, in particular, cooling water and paper and pulp mill systems which employ a combination of bromonitrostyrene and a quaternary ammonium cationic compound as the slime control agent, specifically cetyl trimethyl ammonium bromide and its derivatives.

In the practice of the invention, the combination is added to the particular system being treated; for example, cooling water systems, paper and pulp mill systems, pools, ponds, lagoons, lakes, etc. in a quantity adequate to control the slime-forming microorganisms which are contained by, or'which may become entrained in, the system which is treated. It has been found that such compositions and methods control the growth and occurrence of such microorganisms as may populate these particular systems. As has been documented, bromonitrostyrene, although quite effective as a biocide, has the added advantage of being easily detoxified. Accordingly, the present invention seeks to make use of the biocidal activity, further enhanced by the inclusion of the quaternary compound, with the knowledge that pollutional standards can be complied with.

Bromonitrostyrene or, more specifically, betabromobetanitrostyrene (the cis, trans or mixed forms) possesses the generic formula C H CH=CBrNO and the structural formula EXAMPLE l Synergism was demonstrated by adding Compound A and Compound B in varying ratios and over a range of concentrations to liquid nutrient agar medium (Tryptone Glucose Extract Agar) at approximately C. After the medium had solidified in Petri plates, it was inoculated with a bacterial suspension. Following two days incubation, the lowest concentration of each ratio which prevented growth on the agar medium was taken as the end point. End points for the various mixtures were'then compared with end points for the pure active ingredients working alone in concomitantly prepared agar medium plates. Synergism was determined by the method described by F. C. Kull, P. C. Eisman, H. D. Sylwestrowicz and R. L. Mayer, APPLIED MICROBI- OLOGY, 9, 538-41, (1946), and the relationships,

l is synergism, 1 is antagonism and 1 is additivity where,

Q =Quantity of Compound A, acting alone, producing an end point Q1; Quantity of Compound B, acting alone, producing an end point Q,, Quantity of Compound A, in the mixture, producing an end point Qa Quantity of Compound B, in the mixture, producing an end point For mixtures of Compounds A and B, and for Compound A and Compound B acting alone, the following results were observed.

Summary of synergistic activity of varying percentages of the cetyl trimethyl ammonium bromide compound and betabromo-betanitrostyrene: SYNERGISTIC COMBINATION Compound A: Betabromo-betranitrostyrene Compound B: Cetyl trimethyl ammonium bromide TABLE I TEST ORGANISM AEROBACTER AEROGENES Weight Ratio Quantities Producing End Points 129ml of A B QA QB Mixture QA Qu QB/Qb QH Qb are mixed, the resulting mixtures possess a high degree of slimicidal activity which could not have been predicted beforehand from the known activity of the individual ingredients comprising the mixture. Accordingly, it is therefore possible to produce a more effective slime-control agent than has previously been available. Because of the enhanced activity of the mixture, the total quantity of biocide required for an effective treatment may be reduced. In addition, the high degree of biocidal effectiveness which is provided by each of the ingredients may be exploited without use of the higher concentrations of each.

To demonstrate the synergism which is provided by the inventive combinations of compounds, the data as set forth inthe Table below was developed.

The mode of establishing the synergistic behavior of the compositions of the present invention is a widely used and an industrially acceptable procedure. Al-- ing towers. Moreover, this microorganism is difficult to control and/or kill and accordingly its existence does give rise to troublesome slime. In view of the foregoing, it can then be appreciated that since Aerobaczer aerogecooling water the feeding of the inventive compositions must be designed to compensate for blowdown in those systems which employ that expedient.

Although the styrene compound has been limited in is Prevaieht in most siime'afteeted systems and 5 this description to a specific styrene, it is obvious that since this microorganism is difficult to control or kill, li h dif i f hi compound ld l opert t O Control Of this microorganism is maintained, ate in the same manner. These modifications would be for an Ptaetieai P p the tetai miefeeigahism obvious to the worker once apprised of the invention. Population with its different types is Considered Accordingly, modifications of this nature are included Q 10 within the general scope of the invention.

when the inventive Compositions are p y in As would be expected, the inventive composition the treatment of cooling or paper mill water, they are may b dded to the cooling water or paper and pulp preferably utilized in the form of relatively dilute soluill t m at any onv nient point, Naturally, in tions or dispersions. For'example, a preferred solution h h or nomcircnlatihg Systems, h i- Comprises between 5 and 65% y Weight of the y tion must be added upstream from the point or points glStlC combination in admixture With various solvents at which microorganism control is desired In circularand solubilizing agents. An example of such a synergisi t s r pulp and paper systems, the compositic composition comprises 10% by weight of bromonitions may be added at any point provided that the time trostyrene, 10% of cetyl trimethyl ammonium bromide lapse and the conditions experienced between point of and the remainder composed of such materials as suraddition and the point at which the effect of the comfactants, organic solvents and/or water. position is experienced are not so drastic as to result in Surfactants such as the alkylaryl polyether alcohols, the neutralization of the effect of the composition. polyether alcohols, alkyl benzene sulfonates and sulr fates, and the like, may also be employed to enhance SLIME CONTROL EFFECTIVENESS the dispersibility and stability of these formulations. The inventive methods and materials were tested The forgoing solutions of the biocidal compositions are with respect to their performance in the eOnn-ei of utilized in Order to insure h i P h uhitjotm slime formation in industrial systems. In this test an inpersibility of the biocides w1th1n the industrial water dustrial reeh-eulatihg water was obtained f asystem which is treated. It has been found that either aqueous which was currently experiencing problems in respect -aq o ts are generally suitable in the to the formation of slime by microorganisms. Such tests preparation of composltlons of the invention. For exdo not demonstrate the effieieney f the biocide ample, Organic solvents such as methyl eeiiosoive and ployed with respect to specific species of microorganaiiPhatie and aromatic hydrocarbons kerosene isms but instead supply a practical demonstration of the can be used quite sueeesstuiiy- Based upon the syhet" efficacy of the biocide tested in relation to those comgism study as outlined above, it was ascertained that in munities f microorganisms which have evidenced the treatment of P p miii and cooling water effective their ability to form slime in actual industrial systems. biocidal action is obtained when the concentration or treatment level of the combination or admixture of bio- In testing f recirculating water samples, a Substrate cities is between Parts P miiiioh and 1000 Parts evaluation was employed. In such testing, identical por- P miiiioh, and Preferably between 1 and 100 Parts Pe 40 tions of water samples are treated with varying concenmiiiioh, based P the total eehteht of the system trations of biocide and two portions are left untreated treated, such as the total q y of cooling Water or to serve as controls. The control portions are plated for paper mill Watertotal count at the beginning of biocide treatment and The compositions may also be utilized for the P all portions are plated for total count at some suitable vation of slurries and emulsions containing carbohyi i d fter b i i bi id t t t, (hates, Proteins, fats, Oils, Dosage ieyeis for this Using the counts obtained from the platings, the per- P p range in the vieihity 0t to centage kill (based on the initial control count) may be The Compositions of the ihvehtieh which can be W calculated. in the following example, the water sample pared y mereiy combining the respective ihgt'ediehts was taken from a paper machine headbox sample from and mixing thoroughly at stahdatd conditions may he a paper mill located in the northeastern United States. fed continuously to the treated system, e.g. by means of a metered P p or y be fed Periodically at ihter- For the purposes of comparison, a composition of 1 calculated to control the growth of slime-forming this invention was evaluated with two recognized comorganisms in the system. Naturally, in the treatment of merciai i id Quantity of Percent Kill Biocidal Material Biocide (ppm) After 3 Hours (5%) Betabromo Betanitrostyrene 5 36 (5%) Cetyl Trimethyl Ammonium l0 59 Bromide 25 96 Inert 50 97 99 Pentachlorophenol (10% Active) 5 0 10 0 2s 4 50 23 I00 43 Sodium dimethyldithiocarbamate (10% Active) 1(5] 8 25 0 so 6 I00 22 EFFICACY RELATIVE TO FUNGI In order to ascertain whether in fact the inventive compositions were effective in controlling fungi, evaluations were made following the procedure described by Shema et al., JOURNAL FOR THE TECHNICAL AS- SOCIATION OF THE PULP AND PAPER INDUS- TRY, 36, A-30A, 1953. The described procedure generally entails incorporating the biocide under test in a nutrient substrate such as agar, malt, etc. and pouring the resulting medium in a Petri dish and allowing the medium to solidify. A button of fungus inoculum is placed on the surface of the solidified medium and the medium is incubated for a period of 14 days. After the period, the diameter of the colony is measured and compared with the diameter of the button of inoculum originally placed upon the surface. If there is no increase in the diameter, the growth of the fungus is considered to be completely inhibited and the treatment level which effectuates this is considered the inhibitory concentration.

The fungi species utilized as the test microorganism 'to evaluate the efficacy of the present compositions were Penicillium expansum and Aspergillus niger. The study revealed that the above 10% active composition of this invention inhibited the growth of Penicillium expansum at a treatment level of 100 ppm and 300 ppm completely inhibited the growth of Aspergillus niger.

BACTERICIDAL EFFECTIVENESS The bactericidal effectiveness of a 50/50 mixture of the two components of this invention (10% active) is demonstrated by the following data in which the inhibiting power is shown in comparison with two commercial biocides. Aerobacter aerogenes was employed as the test organism and a substrate technique was utilized. Specifically, the biocidal mixture was added gradually increasing quantities to nutrient agar media which was then innoculated with Aerobacter aerogenes. The preparation was then incubated for 48 hours. The below values indicate the quantity of biocide required to achieve complete inhibition of the growth of the test organism.

Aspergillus niger, it is apparent from the foregoing evaluations and studies that the inventive composition will effectuate the claimed objective of controlling microorganisms of aqueous systems.

It should be noted that while the preponderance of evidence has been derived from the treatment of samples taken from paper and pulp mill aqueous systems, the compositions and methods of the present invention are broadly applicable to the treatment of aesthetic waters as well as industrial waters such as cooling waters which are plagued by deposits formed by slime-forming organisms, or by the very presence of such organisms.

Having thus described the invention, we claim:

1. A composition for the control of the growth of the microorganism Aerobacter aerogenes in aqueous systems in which said microorganism is found comprising betabromobetanitrostyrene and cetyl trimethyl ammonium bromide, wherein the weight ratio of the styrene to the bromide ranges from about 15:85 to about 95:5 respectively.

2. The composition of claim 1 where said ratio is about :50.

3. A method for controlling the microorganism Aerobacter aerogenes in an aqueous system in which said microorganism is found which comprises contacting said microorganism in said system with a growth-preventing amount of a composition comprised of betabromobetanitrostyrene, and cetyl trimethyl ammonium bromide, wherein the weight ratio of the styrene to the bromide ranges from about 15:85 to about 95:5 respectively.

4. The method of claim 3 where said ratio is about 50:50.

5. The method of claim 3 wherein said composition is added to said system in an amount of from about 0.5 to about 1000 parts by weight of said composition per million parts by weight of said aqueous system.

6. The method of claim 5 where said composition amount is from about 1 to about 100 parts per million of said aqueous system.

Biocide Materials Inhibition quantity (ppm) 1. Beta bromo-beta nitrostyrene (5%) Cetyl trimethyl ammonium bromide (5%) 2. RX'-38 3. Pentachlorophenol (l0% active) Accordingly, since the waters of pulp and paper mills and the water of cooling water systems generally predominately contain bacteria such as Aerobacter aerogenes and some fungi such as Penicillium expansum and 

2. The composition of claim 1 where said ratio is about 50:50.
 3. A method for controlling the microorganism Aerobacter aerogenes in an aqueous system in which said microorganism is found which comprises contacting said microorganism in said system with a growth-preventing amount of a composition comprised of betabromo-betanitrostyrene and cetyl trimethyl ammonium bromide, wherein the weight ratio of the styrene to the bromide ranges from about 15:85 to about 95:5 respectively.
 4. The method of claim 3 where said ratio is about 50:50.
 5. The method of claim 3 wherein said composition is added to said system in an amount of from about 0.5 to about 1000 parts by weight of said composition per million parts by weight of said aqueous system.
 6. The method of claim 5 where said composition amount is from about 1 to about 100 parts per million of said aqueous system.
 7. The method of claim 5 wherein the aqueous system is that of a cooling water system.
 8. The method of claim 5 wherein the aqueous system is that of a pulp and paper mill system. 